Elden Ring's Shadow of the Erdtree DLC apparently has no definitive ending, and won't impact the plot of the main game.
Elden Ring game director and FromSoftware studio head Hidetaka Miyazaki was recently interviewed by Chinese outlet Campfire Camp, and was asked about whether Shadow of the Erdtree has multiple endings. Miyazaki firstly reveals that the DLC doesn't have a definitive ending, unlike the conclusion of a full-fledged game like Elden Ring.
FromSoftware DLCs have a habit of this. Once the player has 'completed' a DLC expansion like Bloodborne's The Old Hunters, or Dark Souls' Artorias of the Abyss, they simply go back to playing the base game, rather than arriving at an extensive list of credits like you would with the main game itself.
However, Miyazaki does say that in terms of story pathways, Shadow of the Erdtree has multiple choices the player can make throughout. It sounds like, from these comments, although Shadow of the Erdtree won't have a 'traditional' ending as such, it will have a conclusion for its story, and could feature multiple branching narrative pathways.
Elsewhere in the same interview, Miyazaki reveals Shadow of the Erdtree will be Elden Ring's only DLC, but he doesn't rule out an entire sequel to the RPG eventually being made at some point in the future. Miyazaki points to FromSoftware's development attitudes in this, believing that the studio often leaves the door open to further entries.
